In a portable terminal apparatus such as a cellular phone, two or more functions such as a telephone number retrieval function, a game function and a camera function are allocated to their associated buttons as a previously fixedly decided menu and, when a user selects one of the buttons, the user can execute a desired function.
Recently, as the portable terminal has advanced in function, there has been run short of the number of buttons to which the functions of the portable terminal are allocated. To resolve the shortage of the number of operation buttons, at the present, there is proposed a portable terminal in which, in addition to operation buttons “0”˜“9”, there are provided two or more guide operation buttons and, by using one guide operation button, any one of two or more functions guided and displayed on the guide display part of the portable terminal can be selected.
Also, there is also provided a portable terminal apparatus in which the colors of the backlights of guide operation buttons are linked to the display colors of guides to thereby prevent the wrong depression of the guide operation buttons (for example, see the patent reference 1).    Patent Reference 1: JP2003-209610